2004 Corolla Engine, to replace or not replace

I need some advice as to how to proceed with my 2004 Toyota Corolla. It has approximatle 350,000 mile on it (odometer failed at 299,999). I noticed an extreme loss of power. I couldn’t reach 60 MPH on the interstate going up hill. I changed plugs and tested fuel pressure (48 psi, within spec). Tested after and had even less power. I had to limp home at 25 MPH. I noticed that the car is running a lot hotter than it used to run. I did a compression test (Dry: 1-122.5 psi, 2-140 psi, 3-135 psi, 4-135 psi Wet: 1-245 psi, 2-210 psi, 3-210 psi, 4-210 psi),

Now comes the crux of my question. Is the engine shot? Should I replace both engine (cheapest I can find online is $1,300) and transmission (cheapest $400)? I would be attempting to do the work on my own. I have some experience working on cars; oil changes, replacing radiators, starters, and spark plugs. Is this going to be too big of a job for a home gamer/weekend warrior? Any advice is greatly appreciated.

Yes this is a big job plus you will have to pay to dispose of the old engine and transmission. That 1300.00 engine on line must be used and might not last very long.

Sorry , but this thing has reached the end of it’s life span . Replacement vehicle time.


After 16 years and ~350,000 miles, I’d put that money towards a new car. Too many things with that much mileage and time could be getting ready to go


I’m not liking the way this is heading…

I was hoping to hear that it would be a pretty easy engine swap.

@ VOLVO-V70-it is a used engine from a salvage yard with 86K on it.

And you have no idea if this engine is in any better shape than your own. It’s a 16 year old econobox, just junk it.


You never said whether the check engine light was on… Nor did you check for an exhaust restriction… the latter is important if swapping engine.

But those compression readings are pretty bad…

If the engine is the same year and everything for your car, I’d swap the engine and transmission at the same time as both are on their last legs. It is a do-able job if you take pictures, mark wiring, be diligent about keeping track of bolts and such and take your time.

That said, wheel bearings, CV joints and shafts are all likely ready to die and need replacing. If the engine is out, it would be stupid not to replace the oil pan gasket and rear seal as well as the front trans seal while they are out and you can reach them. If the engine has a timing belt, 86K or not, it must be replaced and that includes the front seal and the water pump… You see where this is going? $$$$ and time.

And if this is in a state where salt is used on the roads in the winter… forget this job and scrap the car. Rust is already about to kill it.


Sorry but IMHO it’s time to move on. My Corolla is a 2009 in good condition with 120k and if it needed an engine I’d get rid of it. A dealer might sell a really nice 2004 for $6k, which is more than a private seller would get, and at 350k yours likely doesn’t fit that category. Plus, I know a guy who swapped out the engine in a Cressida and he didn’t describe the experience as fun.


I put a vacuum gauge on the intake manifold side and read 11 in Hg on a cold engine. I lost all vacuum as soon as I touched the throttle. It would stabilize around 8 mm Hg at 2,000 RPM. I could not see a slow loss of vacuum at 2,000 RPM. Is there another way to determine if the exhaust is clogged. The amount of heat that is being generated from the exhaust manifold makes me think something is going on there.

No check engine light.

I’m in the south east, so no worries with the rust.

Most definitely does not meet that description. It’s my junker commuter car. But there is some hard to describe value about having a total junk box. It’s almost like wearing a badge of honor to keep the thing on the road.

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Oh, I understand completely. In the mid 80’s around the time my wife and I were first married I owned a 1977 Oldsmobile Omega for a short time. It became known as “my valuable $300 car.” It was both challenging and rewarding to keep it running until the day it simply wouldn’t any more. But you need to decide if a 16 year old junker is “the hill you want to die on.”


If you pull the front O2 sensor and install a sensitive pressure gauge, a converter that is plugged will show positive pressure. Anything over 1 psi at idle is bad. Rev it up and you might see 5 psi or more. Dead giveaway the cat has done a melt down.

Since the rings are worn, the amount of oil run through that cat has likely melted it. If you find pressure, you can open the exhaust right before the cat and give it a quick run… in the day… it will wake up your neighbors.

If it is clogged there might be a little more life in the old girl.


It sounds to me like the engine has a lot of wear, but is still in serviceable condition, although there might be an exhaust restriction (perhaps the catalytic converter). Since you live outside of CA and NY, you can buy a cost-effective aftermarket cat online, and you can add Restore to the motor oil to help the performance and oil consumption. (Remember to always do a fresh oil and filter change before adding the Restore for best results.)

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If you are not ready to say goodbye to your Corolla, I have another suggestion. Instead of buying a used engine/tranny and doing a lot of work when you don’t know whether they are good…buy another low-mileage 2004 Corolla and use your current one for parts. This would be the “highest usage” for your old car.
I’m sure that your wife and neighbors will not mind a parts car parked on the front lawn, and your old favorite car can stay with you for years.

The compression is pretty bad and that is backed up by the poor vacuum reading of 11 inches. As for losing vacuum when you blip the throttle that is entirely normal. It’s doing what it should do.
An engine in good condition should have a manifold vacuum reading at idle of around 19 to 21 inches with a rock steady gauge needle.

If it were me I would say goodbye to it and I’m of the type who keeps a car nigh on forever. On top of engine or trans issues everything else on it has 350k miles also and as mentioned buying a used engine or transmission is always a flip of the coin. Salvage yards always say everything in the yard is “guaranteed good” when the reality is they do not know and individuals will often lie through their teeth.

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Is that supposed to be a joke . . . ?!


I’m betting it is sarcasm.

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Hope so . . .

Just my two cents. Take that $ 1600 as a down payment on a newer car maybe 2 years old. Mostly because its your life .And newer cars have abs and airbags guaranteed to work . as well as things that wont rust tomorrow letting your life be in danger.

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Don’t put a penny into that car.Get wrid of it because It reached the end of its life.

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This did the trick! I used the low drum of generators (we had a power outage in the neighborhood) to mask the noise of driving around without an exhaust and the, limited as it is, power has returned. I’m going to buy a $100 catalytic converter from eBay and rent tools from Advance Auto. Thanks for all the input and advice. Looks like I can live on this hill for a while longer.

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